Intro. to CHEMICAL REACTIONS Notes

Binder organization

• Tab 1: Reference Sheets• Tab 2: Chemistry Handouts• Tab 3: Math Handouts• Tab 4: HW, Tests, quizzes• Tab 5: Projects

Physical vs. Chemical Change• Physical change: A substance changes

appearance, but it is still that substance– Example: Tearing paper

• Chemical change: A substance actually changes into something else– Example: Burning paper

Chemical Reactions

• Chemical reaction: The process by which one or more substances change to form one or more different substances

• Evidence of Chemical Reactions1. Color change2. Bubbles (gas formed)3. Turns cloudy (solid/precipitate formed)4. Temperature change5. Change in smell

Chemical Reactions

• Chemical reaction: The process by which one or more substances change to form one or more different substances

• Evidence of Chemical Reactions1. Color change2. Bubbles (gas formed)3. Turns cloudy (solid/precipitate formed)4. Temperature change5. Change in smell

Chemical Reactions

• Chemical reaction: The process by which one or more substances change to form one or more different substances

• Evidence of Chemical Reactions1. Color change2. Bubbles (gas formed)3. Turns cloudy (solid/precipitate formed)4. Temperature change5. Change in smell

Chemical Reactions

• Chemical reaction: The process by which one or more substances change to form one or more different substances

• Evidence of Chemical Reactions1. Color change2. Bubbles (gas formed)3. Turns cloudy (solid/precipitate formed)4. Temperature change5. Change in smell

Is it a chemical or physical change?

• Sugar dissolving in tea

Is it a chemical or physical change?

• Logs burning

Is it a chemical or physical change?

• Breaking water up by separating it into hydrogen and oxygen

• 2H2O 2H2 + O2

Is it a chemical or physical change?

• Cutting paper

Is it a chemical or physical change?

• Crushing an aspirin

Is it a chemical or physical change?

• Metal rusting

Is it a chemical or physical change?

• An egg rotting

Is it a chemical or physical change?

• An egg breaking

Writing Chemical Equations

• Reactants = starting materials• Products = ending materials

MgMg MgOMgO++ OO22(s) (g) (s)ReactantsReactants ProductProduct

States of Matter:Solid = (s)Liquid = (l)Gas = (g)Aqueous = (aq)

dissolved in water

Writing Chemical Equations• Example:– Hydrogen gas reacts with oxygen gas to

produce liquid water

HH22 HH22OO++ OO22(g) (g) (l)

““reacts with”reacts with”““combines with”combines with”““is added to”is added to”

““to produce”to produce”““yields”yields”““to make”to make”““synthesizes”synthesizes”

Write the Chemical Equation for the following:• Solid carbon reacts with oxygen gas to

produce gaseous carbon dioxideC(s) + O2(g) CO2(g)

Write the Chemical Equation for the following:• Solid zinc metal is added to an aqueous

solution of hydrochloric acid (HCl) to produce hydrogen gas and aqueous zinc (II) chloride.

Zn(s) + HCl(aq) H2(g) + ZnCl2(aq)